TFP1466
Page 6 of 18
Electric/
Electric
Actuation
System Design Considerations
Because a double interlock preac-
tion system requires time for a drop in
system air pressure to occur (concur-
rently with the response time for the
separate fire detection system) before
it will allow water to enter the system
piping, this system has characteristics
similar to a dry pipe sprinkler system.
Therefore, the system design con-
siderations for a dry pipe system are
normally applied to a double interlock
preaction system, — including: a 30%
increase in design area; a maximum
1 minute water delivery time for system
capacities of 500 gallons (1890 liters)
or more; and, prohibition of gridded
system piping.
As an option, the DV-5
a
Double Inter-
lock Preaction System with Electric/
Electric Actuation may be equipped
with the Model QRS Electronic Accel-
erator to reduce the time to valve actu-
ation following the operation of the
electric detection system and one or
more automatic sprinklers. Refer to
Technical Data Sheet TFP1100 for
details regarding installation require-
ments and pressure ratings.
Note:
Use of the Model QRS Electronic
Accelerator can permit system volumes
of 750 gallons (2840 Liters) without
applying the minimum one minute
water delivery time.
In order to readily perform the System
Inspection Procedure described in
the Care and Maintenance section,
it is recommended that a System
Shut-Off Valve be installed above the
DV-5
a
Valve, as shown in Figure 4. The
System Shut-Off Valve should be a
listed or approved (as appropriate) indi-
cating valve with a supervisory switch
to monitor the normally open position.
Detection System
The Double Interlock Preaction System
With Electric/Electric Actuation Trim
provides for electric operation of the
DV-5
a
Valve by a detection system
consisting of electrical devices such
as heat sensitive thermostats, smoke
detectors, and/or electric manual pull
stations. Information on the various
types of separately ordered Solenoid
Valves that may be used with this trim
package is given in Technical Data
Sheet TFP2180. Nominal installation
dimensions for the Double Interlock
Preaction System With Electric/Electric
Actuation Trim are shown in Figure 7.
The cross-zone deluge valve releas-
ing panel (automatic control unit)
with battery back-up, fire detection
devices, manual pull stations, and sig-
naling devices, that are utilized with the
Double Interlock Preaction System with
Electric/Electric Actuation must be UL
Listed, ULC Listed, C-UL Listed, or FM
Approved, as applicable.
NOTES:
The normally closed, de-energized
solenoid Valve is separately ordered and
selected based on the required laboratory
approval acceptable to the authority having
jurisdiction. Refer to technical data Sheet
TFP2180 for specific laboratory approvals.
Consult with the authority having
jurisdiction regarding installation criteria
pertaining to electric actuation circuitry.
Due to the functionality of the Model
MRA-1 Manual Reset Actuator, the
release circuit of the releasing panel
need only provide the typical ten
minutes of alarm condition intended
to energize the Solenoid Valve to
SYSTEM PIPING WITH AUTOMATIC SPRINKLERS - NORMALLY DRY
SYSTEM DRAIN VALVE
(NORMALLY CLOSED)
MAIN
DRAIN VALVE
(NORMALLY
CLOSED)
LOCAL
MANUAL
CONTROL
STATION
MAIN
CONTROL VALVE
(NORMALLY
OPEN)
WATER
SUPPLY
DIAPHRAGM CHAMBER
PRESSURE GAUGE
WATER SUPPLY
PRESSURE
GAUGE
MANUAL RESET
ACTUATOR
WATERFLOW
PRESSURE
ALARM
SWITCH
SOLENOID
VALVE
(TYPICALLY
24 VOLTS DC)
ELECTRIC DETECTION SYSTEM
(TYPICALLY 24 VOLTS DC)
HEAT DETECTORS, SMOKE DETECTORS,
MANUAL PULL STATIONS, ETC.
CROSS-ZONE
DELUGE VALVE
RELEASING PANEL
(AUTOMATIC
CONTROL UNIT
WITH BATTERY
BACK-UP)
POWER
SUPPLY
(TYPICALLY
120 VOLTS AC)
MANUAL ELECTRIC PULL STATION
(AS REQUIRED)
ZONE
1
AUTOMATIC
AIR/NITROGEN
SUPPLY
TYPICALLY
15 PSI
ZONE
2
SUPERVISORY
LOW PRESSURE
ALARM SWITCH
DV-5A
VALVE
RESTRICTION
DRAIN
DRAIN
DRAIN
DRAIN
DRAIN
SYSTEM
SHUT-OFF VALVE
(NORMALLY OPEN)
SYSTEM AIR
PRESSURE
GAUGE
WATER SUPPLY SHUT-OFF
(NORMALLY OPEN)
DIAPHRAGM
CHAMBER SUPPLY
CONTROL VALVE
(NORMALLY OPEN)
DIAPHRAGM CHAMBER
SUPPLY CONNECTION
FIGURE 4
DV-5
a
VALVE - DOUBLE INTERLOCK PREACTION ELECTRIC/ELECTRIC ACTUATION
SCHEMATIC DIAGRAM
